The present invention relates generally to a sorting system with air flow control. More particularly, this invention pertains to improvements in an apparatus and method for controlling air flow and product sorting in an air control sorting system.
Several United States Patents are directed to conveyors and sorting devices. These include U.S. Pat. No. 2,824,665, issued to Lamouria on Feb. 25, 1958; U.S. Pat. No. 3,329,469, issued to Stadelman on Jul. 4, 1967; U.S. Pat. No. 3,471,013, issued to Haver on Oct. 7, 1969; U.S. Pat. No. 4,609,108, issued to Hristozov et al. on Sep. 2, 1986; and U.S. Pat. No. 5,339,964, issued to Gray et al. on Aug. 23, 1994. One patent worth noting is U.S. Pat. No. 5,339,964, issued to Gray et al. and assigned to SIMCO/Ramic Corporation which discloses a discharge chute which has vents 44 and 45 which allow air to escape from the discharge chute. However, this patent is limited in its teachings because it fails to teach the advantages of the present invention.
The prior art fails to teach the advantages the present invention in controlling the movement of the rejected waste product in the discharge chute product flow through the utilization of a product rake and/or relief valves. Therefore, what is needed is an improved method and apparatus for controlling the movement of product in an entraining carrier stream.
The present invention is directed to a modification of a discharge chute with a product rake and/or a relief valve to prevent the circling upward movement of waste paper from product flow within the discharge chute.
One preferred embodiment of the present invention utilizes a product rake for dragging the variable product flow for separating the product from the entraining carrier stream. The preferred design of the product rake includes one or more fingers that project into the product flow. The finger(s) are adapted to capture the product as combings during product flow and direct the combings to a discharge area.
A method is taught by the present invention for controlling the flow of a product entrained in a carrier stream within a housing. The method includes providing a carrier-permeable, but product-impermeable capturing barrier that is mounted within the housing; capturing the product with the barrier during a product flow period, and allowing the product to leave the barrier.
Another improvement of the present invention utilizes an auxilary blower which is adapted to provide a slight updraft of the air from the discharge chute into the main air stream of paper to minimize unwanted paper entering the chute. Another improvement to the present invention utilizes a relief valve mounted in the wall of the discharge chute and adapted to relieve excess air pressure in the chute to reduce blow back of discharge paper from the chute into the main air stream. The relief valve includes a valve frame mounted to the discharge chute that forms a flow opening out of the discharge chute. The flow opening is used to exhaust at least a portion of the product flow or carrier from the discharge chute. The flow opening is covered by a valve flap that is hingably mounted to the valve frame. The valve flap is adapted to selectively adjust the exhausting of the product flow through the flow opening in relation to the pressure of the product flow within the exhaust discharge chute. The relation of the exhaust flow to the pressure may be modified or controlled by a flow vane operating in association with the valve flap. This pressure reduction can be used to control the flow of the product flow within the discharge chute.
A method is also taught by the present invention for reducing the return product flow from the discharge chute to the main air stream caused by the eddy flow within an airstream inside an enclosure. This method includes providing an exhaust path from the enclosure for the airstream in the area of the eddy current.